Image capture device, image capture device control method, and image capture device control program

Abstract

To provide an imaging device that can reduce unnecessary event recording when a vehicle is traveling.SOLUTION: An image capturing unit 10 captures images of the interior or exterior of a vehicle to generate image data 31. A vibration detection unit 20 detects vibrations of the vehicle. A threshold setting unit 41 sets a threshold value to determine whether or not an event has occurred for which the image data 31 should be saved, based on a detected value of the vibration of the vehicle. An event detection unit 43 compares the detected value with the threshold value to detect the occurrence of the event. A recording control unit 44 records the image data 31 for a predetermined period of time before and after the occurrence of the event onto a recording medium 50 for storage. A threshold value updating unit 45 updates the threshold value to be used in the next unit interval based on the maximum detected value for each unit interval.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an imaging apparatus, a control method for an imaging apparatus, and a control program for an imaging apparatus. [Background technology]

[0002] Patent Document 1 describes a drive recorder that, when it determines that the vehicle is parked, controls a threshold value for determining whether or not detected vehicle swaying is abnormal based on at least one of video, illuminance information, and sound information around the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6583392 Summary of the Invention [Problem to be solved by the invention]

[0004] The drive recorder described in Patent Document 1 compares the vehicle shaking detected while the vehicle is parked or traveling with a threshold value, and records captured image data if the vehicle shaking is determined to be abnormal (hereinafter referred to as event recording). For this reason, depending on the threshold value setting, shaking on a bad road with poor road conditions or vibrations specific to the vehicle may be determined to be abnormal while the vehicle is traveling, and unnecessary event recording may be frequently performed even when there is no abnormality such as a collision.

[0005] An object of the present invention is to provide an imaging device, a control method for an imaging device, and a control program for an imaging device that can reduce unnecessary event recording while a vehicle is traveling. [Means for solving the problem]

[0006] The present invention provides an imaging device comprising: an imaging unit that images the interior or exterior of a vehicle to generate image data; a vibration detection unit that detects vehicle vibrations; a threshold setting unit that sets a threshold for determining whether an event for which image data should be saved has occurred based on a detection value of the vehicle vibration detected by the vibration detection unit; an event detection unit that compares the detection value of the vehicle vibration detected by the vibration detection unit with a threshold set by the threshold setting unit to detect the occurrence of an event; a recording control unit that, when the event detection unit detects the occurrence of an event, records image data for a predetermined period before and after the occurrence of the event, including the time when the event occurred, on a storage recording medium; and a threshold update unit that obtains the maximum detection value of the vehicle vibration for each unit section which is a predetermined time or distance traveled by the vehicle, calculates a threshold to be used in the next unit section based on the maximum detection value, and updates the threshold set by the threshold setting unit.

[0007] The present invention provides a control method for an imaging device, which acquires vehicle vibrations detected by a vibration detection unit, sets a threshold value based on the detection value of the vehicle vibrations to determine whether an event has occurred for which image data generated by an imaging unit by imaging the interior or exterior of the vehicle should be saved, compares the detection value of the vehicle vibrations with the set threshold value to detect the occurrence of an event, and if an event is detected, records image data for a predetermined period before and after the event, including the time when the event occurred, on a storage recording medium, obtains the maximum detection value for each unit section, which is a predetermined time or distance traveled by the vehicle, calculates a threshold value to be used in the next unit section based on the maximum detection value, and updates the set threshold value.

[0008] The present invention provides a control program for an imaging device that causes a computer mounted on the imaging device to execute the following steps: acquiring vehicle vibrations detected by a vibration detection unit; setting a threshold for determining whether an event has occurred for which image data generated by the imaging unit by imaging the interior or exterior of the vehicle has been saved based on the detection value of the vehicle vibration; comparing the detection value of the vehicle vibration with the set threshold to detect the occurrence of an event; if the occurrence of an event is detected, recording image data for a predetermined period before and after the occurrence of the event, including the time when the event occurred, on a storage recording medium; and calculating the maximum detection value for each unit section, which is a predetermined time or distance traveled by the vehicle, calculating a threshold to be used in the next unit section based on the maximum detection value, and updating the set threshold. Effect of the Invention

[0009] According to the imaging device, the control method for the imaging device, and the control program for the imaging device of the present invention, it is possible to reduce unnecessary event recording while the vehicle is traveling. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of an imaging device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of a road on which a vehicle equipped with an imaging device travels. [Diagram 3] FIG. 3 is a diagram for explaining functions of the imaging device according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart illustrating an example of processing executed by the CPU included in the imaging device according to the first embodiment of the present invention. [Diagram 5] FIG. 5 is a block diagram showing an example of the configuration of an imaging device according to the second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining functions of the imaging device according to the second embodiment of the present invention. [Figure 7]FIG. 7 is a flowchart illustrating an example of processing executed by the CPU included in the imaging device according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an image capture device, a control method for an image capture device, and a control program for an image capture device according to each embodiment will be described with reference to the accompanying drawings. In the description of the drawings, the same parts are given the same reference numerals and the description will be omitted.

[0012] [First embodiment] [Example of imaging device configuration] An example of the configuration of an imaging device 1 according to a first embodiment will be described with reference to Fig. 1. The imaging device 1 is mounted on a vehicle V shown in Fig. 2, and records image data 31 indicating the driving situation of the vehicle V. The imaging device 1 is attached, for example, to the back of a rearview mirror of the vehicle V. The imaging device 1 is, for example, a so-called drive recorder, and includes an imaging unit 10, an acceleration sensor 20, an internal memory 30, a CPU (Central Processing Unit) 40, and a recording medium 50, as shown in Fig. 1. At least the CPU 40 and the internal memory 30 may be configured by a microcomputer.

[0013] The imaging unit 10 captures an image of the inside or outside of the vehicle V to generate image data 31. The imaging unit 10 includes, for example, a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The imaging unit 10 is disposed at a position where it captures at least the traveling direction (forward) of the vehicle V. The image data 31 is generated in a format conforming to a preset arbitrary method. For example, the image data 31 may be data compressed by a compression method such as H.264 (MPEG-4 AVC) or H.265 (HEVC). Note that MPEG-4 AVC stands for Moving Picture Experts Geoup Advanced Video Coding, and HEVC stands for High Efficiency Video Codec. The recording format of the image data 31 may be any of MP4, MOV, AVI (Audio Video Interleave), etc. The compression method and recording format of the image data 31 are not limited to these.

[0014] The acceleration sensor 20 is, for example, a three-axis acceleration sensor that detects acceleration in three axial directions of the x-axis, y-axis, and z-axis, and is mounted at an arbitrary position on the imaging device 1. The acceleration sensor 20 functions as a vibration detection unit that detects vibrations of the vehicle V. In a typical configuration of the acceleration sensor 20, a weight (weight, mass) of a movable part is vibrated by acceleration, and the movable part is displaced by the balance with the reaction force of a spring that supports the weight. The displacement of the movable part is converted into an electric signal by a displacement detection unit attached to the weight or a strain detection unit that detects strain of the spring, and the signal is processed and output by a peripheral electronic circuit. The main peripheral electronic circuits are a signal conversion unit that amplifies the signal detected by the detection mechanism and performs analog / digital conversion, an output unit that outputs the converted signal, and the like.

[0015] The acceleration sensor 20 detects the acceleration applied to the acceleration sensor 20, and outputs detection values ​​of the positive and negative sides of the vibration of the vehicle V according to the detected acceleration. The acceleration sensor 20 is connected to the CPU 40, and outputs detection values ​​of the positive and negative sides of the vibration of the vehicle V to the CPU 40. Note that the acceleration sensor 20 may be a 1-axis or 2-axis acceleration sensor instead of a 3-axis acceleration sensor.

[0016] The internal memory 30 is composed of a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The ROM is used as a storage area for a control program (not shown) executed by the CPU 40. The RAM is used as a working area for the CPU 40, and also as a buffer area for temporarily storing image data 31 for a predetermined period of time (several seconds to several minutes).

[0017] The CPU 40 operates according to a control program stored in the internal memory 30, and comprehensively controls each unit of the imaging device 1. The CPU 40 reads and executes the control program stored in the internal memory 30 to realize each function described below.

[0018] The recording medium 50 is, for example, a memory card or the like, and is a flash memory capable of recording image data 31 captured by the imaging unit 10. The recording medium 50 is, for example, inserted into a slot provided in the imaging device 1 for use, and is configured to be removable from the imaging device 1. The recording medium 50 may be a non-volatile memory such as a flash memory built into the imaging device 1. The recording medium 50 may be configured as a magnetic storage device such as a hard disk drive. An event storage area (not shown) of the recording medium 50 is a storage area in which overwriting of the recording medium 50 is prohibited, and image data 31 for a predetermined period in which an event is determined to have occurred by the recording control unit 44 is transferred from the internal memory 30 and recorded as image data 51.

[0019] Next, a description will be given of the recording operation of the imaging device shown in Fig. 1. Image data 31 captured by the imaging unit 10 is cyclically recorded in the recording area of ​​the internal memory 30. That is, the image data 31 is recorded sequentially from the first logical address (or physical address) in the internal memory 30, and when the image data 31 is recorded up to the last logical address (or physical address), the recording start position returns to the first logical address (or physical address) again, and the image data 31 is overwritten as it is.

[0020] If the detection value detected by the acceleration sensor 20 exceeds a predetermined threshold while such a cyclical recording method is being executed, the occurrence of an event is detected under the control of the CPU 40. The occurrences that the imaging device 1 wishes to detect as events are occurrences that are considered to have a high probability of occurring while the vehicle V is traveling, such as sudden acceleration, sudden braking, impact due to sudden steering, vehicle accidents, collisions, and the like.

[0021] Image data 31 for a predetermined period before and after the time when the occurrence of an event is detected is transferred to the recording medium 50 under the control of the CPU 40. This transfer results in the image data 51 before and after the occurrence of the event being recorded on the recording medium 50, which is prohibited from being overwritten. Hereinafter, recording image data 31 for a predetermined period before and after the time when the occurrence of an event is detected may be referred to as "event recording".

[0022] Next, a description will be given of functions of the CPU 40 of the imaging device 1. The CPU 40 includes, as an example of a functional configuration, a threshold setting unit 41, an information acquisition unit 42, an event detection unit 43, a recording control unit 44, and a threshold update unit 45.

[0023] The threshold setting unit 41 sets positive and negative thresholds for determining whether an event for which image data 31 should be stored has occurred based on the positive and negative detection values ​​of the vibration of the vehicle V detected by the acceleration sensor 20. The threshold setting unit 41 sets preset initial thresholds as the positive and negative thresholds when the vehicle V starts traveling. When the positive and negative thresholds are updated by a threshold update unit 45 (to be described later), the threshold setting unit 41 sets the updated positive and negative thresholds as the positive and negative thresholds for determining whether an event has occurred. In addition, the threshold setting unit 41 resets the positive and negative thresholds to the initial thresholds when the vehicle V stops traveling and the power supply of the imaging device 1 is turned off.

[0024] The information acquisition unit 42 acquires detection values ​​of the positive and negative vibrations of the vehicle V detected by the acceleration sensor 20.

[0025] The event detection unit 43 detects the occurrence of an event by comparing the positive and negative detection values ​​of the vibration of the vehicle V acquired from the acceleration sensor 20 with the positive and negative thresholds set by the threshold setting unit 41, respectively. More specifically, when the acquired detection value of the vibration of the vehicle V is on the positive side, the event detection unit 43 judges whether or not the detection value of the vibration of the vehicle V is greater than the positive threshold. Then, when it is judged that the positive detection value of the vibration of the vehicle V is greater than the positive threshold, it detects the occurrence of an event. When the acquired detection value of the vibration of the vehicle V is on the negative side, it judges whether or not the detection value of the vibration of the vehicle V is smaller than the negative threshold. Then, when the negative detection value of the vibration of the vehicle V is smaller than the negative threshold, it detects the occurrence of an event.

[0026] Furthermore, when an event is detected, the event detection unit 43 acquires the time when the event occurred. The time when the event occurred may utilize date and time information acquired from a position information sensor such as GNSS, or may utilize local date and time information generated from a real-time clock connected to the CPU 40. Note that "GNSS" is an abbreviation for "Global Navigation Satellite System," and the position of the vehicle on the ground is detected by receiving radio waves from multiple artificial satellites using a GNSS receiver.

[0027] When the event detection unit 43 detects the occurrence of an event, the recording control unit 44 records image data 31 for a predetermined period before and after the occurrence of the event, including the time when the event occurred, in the storage recording medium 50. The recording control unit 44 transfers the image data 31 generated by the imaging unit 10 during the predetermined period before and after the time when the event occurred and recorded in the internal memory 30 from the internal memory 30 to the recording medium 50, and records it as image data 51. The predetermined period before and after the time when the event occurred may be set to a period of, for example, several seconds to several tens of seconds before and after the time when the event occurred, or may be set to a period longer than that.

[0028] The threshold updating unit 45 obtains the maximum positive and negative detection values ​​of the vibration of the vehicle V, excluding detection values ​​that exceed the positive or negative threshold, for each unit section, which is a predetermined time or distance traveled by the vehicle V. The threshold updating unit 45 calculates the positive and negative thresholds to be used in the next unit section based on the obtained maximum positive and negative detection values, and updates the positive and negative thresholds set by the threshold setting unit 41. The predetermined time traveled by the vehicle V in the unit section may be set to, for example, 30 seconds, and the predetermined distance traveled by the vehicle V may be set to, for example, 1 km. The method of setting the unit section is not particularly limited.

[0029] The threshold update unit 45 determines whether the vehicle V has traveled a unit section that is a predetermined time or a predetermined distance. When the unit section is set to a predetermined distance, the threshold update unit 45 may, for example, detect a change in the position information of the vehicle V to calculate the distance, or may, for example, obtain a vehicle speed pulse to calculate the distance. Since the method of calculating the distance using the change in position information or the vehicle speed pulse is a known technology, detailed description will be omitted. When the threshold update unit 45 determines that the vehicle V has traveled a unit section, it obtains the maximum positive and negative detection values ​​of the vibration of the vehicle V in the unit section, excluding the detection values ​​that exceed the positive or negative threshold value in the traveled unit section. When there is no detection value that exceeds the positive or negative threshold value in the traveled unit section, the threshold update unit 45 obtains the maximum positive and negative detection values ​​of the vibration of the vehicle V in the unit section.

[0030] The threshold updating unit 45 multiplies the maximum positive and negative detection values ​​of the vibration of the vehicle V in the obtained unit section by a predetermined multiple to calculate the positive and negative thresholds to be used in the next unit section. For example, the threshold updating unit 45 multiplies the maximum positive and negative detection values ​​of the vibration of the vehicle V in the unit section by a predetermined multiple "3" to calculate the positive and negative thresholds to be used in the next unit section. Then, the positive and negative thresholds set by the threshold setting unit 41 are updated to the calculated positive and negative thresholds. The predetermined multiple may be, for example, "2", and is not particularly limited.

[0031] Next, an example of the operation of the threshold setting unit 41, the event detection unit 43, the recording control unit 44, and the threshold update unit 45 will be described with reference to FIGS.

[0032] In FIG. 2, a vehicle V equipped with an imaging device 1 is traveling on a road with one lane in each direction. The vehicle V starts traveling from a point A, and travels a unit section D1, which is a predetermined distance from point A to point B. After traveling the unit section D1, the vehicle V travels a unit section D2, which is a predetermined distance from point B to point C. After traveling the unit section D2, the vehicle V travels a unit section D3, which is a predetermined distance from point C to point D. It is assumed that the vehicle V continues traveling after traveling the unit section D3. A bad road R with poor road surface conditions exists between the unit section D2 and the unit section D3. It is assumed that no events, such as sudden starts, sudden braking, shocks due to sudden steering, vehicle accidents, collisions, etc., which are events to be detected as events, occur while the vehicle V travels through the unit sections D1 to D3.

[0033] Fig. 3 conceptually shows an example of a change in a detection value G of vibration of the vehicle V (hereinafter simply referred to as detection value G) when the vehicle V travels along the road shown in Fig. 2, and positive and negative thresholds for each unit section D1 to D3. Note that the vertical axis of Fig. 3 indicates the detection value, and the horizontal axis indicates the distance.

[0034] At point A where the vehicle V starts traveling, the threshold setting unit 41 sets preset initial thresholds THa and THb as positive and negative thresholds for detecting the occurrence of an event.

[0035] During travel in the unit section D1, the event detection unit 43 detects the occurrence of an event by comparing the detection value G with the positive and negative thresholds THa and THb set by the threshold setting unit 41. In the unit section D1 shown in Fig. 3, the detection value G does not exceed the positive or negative thresholds THa and THb, so the event detection unit 43 does not detect the occurrence of an event. In this case, no event recording is performed in the unit section D1.

[0036] The threshold updating unit 45 determines whether the vehicle V has traveled through a unit section. In Fig. 3, the threshold updating unit 45 determines that the vehicle V has traveled through a unit section D1 at the time when the vehicle V reaches the point B. In the unit section D1, the detection value G does not exceed the positive or negative threshold values ​​THa and THb, so the threshold updating unit 45 calculates the maximum values ​​M1a and M1b of the detection value G on the positive and negative sides within the unit section D1.

[0037] The threshold updating unit 45 multiplies the determined maximum values ​​M1a, M1b by a predetermined multiple "3" to calculate the positive and negative thresholds TH2a, TH2b to be used in the next unit section D2. Then, the positive and negative thresholds THa, THb set by the threshold setting unit 41 are updated to the calculated positive and negative thresholds TH2a, TH2b.

[0038] The vehicle V then travels through unit section D2. A rough road R exists in unit section D2. Therefore, the detection value G in unit section D2 reflects the vibration of the vehicle V caused by the rough road R and is generally greater than that in unit section D1. In unit section D2, threshold setting unit 41 sets updated positive and negative thresholds TH2a and TH2b as the positive and negative thresholds.

[0039] During traveling through the unit section D2, the event detection unit 43 compares the detection value G with the positive and negative thresholds TH2a, TH2b set by the threshold setting unit 41, respectively, to detect the occurrence of an event.

[0040] The recording control unit 44 performs event recording of the image data 31 for a predetermined period EV1 before and after the occurrence of the event, including the time when the event detection unit 43 detected the occurrence of the event. The recording control unit 44 also performs event recording of the image data 31 for a predetermined period EV2 before and after the occurrence of the event, including the time when the event detection unit 43 detected the occurrence of the event.

[0041] The threshold update unit 45 determines that the vehicle V has traveled through the unit section D2 at the time when the vehicle V reaches the point C. The threshold update unit 45 calculates maximum values ​​M2a, M2b of the positive and negative detection values ​​G within the unit section D2, excluding the detection value G that exceeds the positive threshold TH2a within the unit section D2.

[0042] The threshold updating unit 45 multiplies the calculated maximum values ​​M2a, M2b by a predetermined multiple "3" to calculate the positive and negative thresholds TH3a, TH3b to be used in the next unit section D3. Then, the positive and negative thresholds TH2a, TH2b set by the threshold setting unit 41 are updated to the calculated positive and negative thresholds TH3a, TH3b. In this way, by updating the positive and negative thresholds of the unit section D3 based on the detection value G of the vibration of the vehicle V detected in the unit section D2 where the detection value G becomes large due to the bad road R, it is possible to use the positive and negative thresholds that reflect the road conditions of the immediately preceding unit section D2 in the unit section D3.

[0043] The vehicle V then travels through unit section D3. Similar to unit section D2, unit section D3 also has a rough road R. Therefore, the detection value G in unit section D3 also reflects the vibration of the vehicle V caused by the rough road R and is generally larger than that in unit section D1. In unit section D3, threshold setting unit 41 sets updated positive and negative thresholds TH3a and TH3b as the positive and negative thresholds.

[0044] While traveling through the unit section D3, the event detection unit 43 detects the occurrence of an event by comparing the detection value G with the positive and negative thresholds TH3a and TH3b set by the threshold setting unit 41. In the unit section D3 shown in FIG. 3, the detection value G does not exceed the positive or negative thresholds TH3a and TH3b, so the event detection unit 43 does not detect the occurrence of an event. In this case, no event is recorded in the unit section D3. Therefore, in the unit section D3, erroneous event recording due to a large detection value G caused by the bad road R, which should not actually be recorded as an event, is avoided.

[0045] The threshold updating unit 45 determines that the vehicle V has traveled through the unit section D3 at the time when the vehicle V reaches the point D. In the unit section D3, the detection value G does not exceed the positive or negative thresholds TH3a and TH3b, so the threshold updating unit 45 obtains the maximum values ​​M3a and M3b of the positive and negative detection values ​​G within the unit section D3. Thereafter, the same process is repeated to update the positive and negative thresholds for each unit section.

[0046] In this way, by updating the threshold value of the vibration of the vehicle V for detecting the occurrence of an event based on the detection value of the vibration of the vehicle V detected for each unit section, it is possible to use a threshold value that reflects the road conditions of the immediately preceding unit section. This makes it possible to prevent the detection value of the vibration of the vehicle V from exceeding the threshold value due to vibration on a rough road or vibration specific to the vehicle, even if an event that is originally to be detected, such as a collision, has not occurred, and the occurrence of the event is detected. This makes it possible to reduce unnecessary event recording.

[0047] [Processing flow of the imaging device] Next, an example of the flow of processing executed by the CPU 40 of the imaging device 1 shown in Fig. 1 will be described with reference to a flowchart of Fig. 4. The CPU 40 starts the processing of Fig. 4 at the timing when the vehicle V starts traveling.

[0048] In step S10, the threshold setting unit 41 sets positive and negative thresholds for determining whether or not an event has occurred for which image data 31 should be stored, based on the positive and negative detection values ​​of the vibration of the vehicle V detected by the acceleration sensor 20. The threshold setting unit 41 sets initial thresholds that have been set in advance as the positive and negative thresholds, during the period from when the vehicle V starts traveling until it travels a unit section that is a predetermined time or distance.

[0049] The process proceeds to step S11, where the information acquisition unit 42 acquires a detection value of the vibration of the vehicle V detected by the acceleration sensor 20.

[0050] The process proceeds to step S12, where the positive and negative detection values ​​of the vibration of the vehicle V acquired from the acceleration sensor 20 are compared with the positive and negative thresholds set by the threshold setting unit 41 to detect the occurrence of an event. When the acquired detection value of the vibration of the vehicle V is on the positive side, the event detection unit 43 judges whether or not the positive detection value is greater than the positive threshold. Then, when it is judged that the positive detection value of the vibration of the vehicle V is greater than the positive threshold, it detects the occurrence of an event. When the acquired detection value of the vibration of the vehicle V is on the negative side, it judges whether or not the detection value is smaller than the negative threshold, and when the negative detection value of the vibration of the vehicle V is smaller than the negative threshold, it detects the occurrence of an event. When the event detection unit 43 detects the occurrence of an event (YES in step S12), the process proceeds to step S13. On the other hand, when the event detection unit 43 does not detect the occurrence of an event (NO in step S12), the process proceeds to step S14.

[0051] In step S13, the recording control unit 44 performs event recording to record image data 31 for a predetermined period before and after the occurrence of the event, including the time when the event occurred, as image data 51 on the storage recording medium 50, and the process proceeds to step S14.

[0052] In step S14, the threshold update unit 45 determines whether the vehicle V has traveled a unit section that is a predetermined time or a predetermined distance. If the vehicle V has traveled the unit section (YES in step S14), the process proceeds to step S15. On the other hand, if the vehicle V has not traveled the unit section (NO in step S14), the process returns to step S11.

[0053] In step S15, the threshold update unit 45 obtains the maximum positive and negative detection values ​​of the vibration of the vehicle V within the unit section, excluding detection values ​​that exceed the positive or negative threshold within the traveled unit section.

[0054] Processing proceeds to step S16, where the threshold update unit 45 multiplies the maximum positive and negative detection values ​​of the vibration of the vehicle V within the unit section obtained in step S15 by a predetermined multiple to calculate the positive and negative thresholds to be used in the next unit section.

[0055] The process proceeds to step S17, where the positive and negative thresholds set by the threshold setting unit 41 are updated to the positive and negative thresholds calculated in step S16, and the process returns to step S11. After that, the CPU 40 repeats the processes of steps S11 to S17 in FIG. 4 until the vehicle V stops traveling and the imaging device 1 is powered off.

[0056] [Effects of the first embodiment] As described above, the imaging device 1 according to the first embodiment includes the imaging unit 10, the vibration detection unit (acceleration sensor) 20, the threshold setting unit 41, the event detection unit 43, the recording control unit 44, and the threshold update unit 45. The imaging unit 10 captures an image of the interior or exterior of the vehicle V to generate image data 31. The vibration detection unit 20 detects vibrations of the vehicle V. The threshold setting unit 41 sets a threshold for determining whether or not an event for which the image data 31 should be stored has occurred, based on a detection value of the vibrations of the vehicle V detected by the vibration detection unit 20. The event detection unit 43 compares the detection value of the vibrations of the vehicle V detected by the vibration detection unit 20 with the threshold set by the threshold setting unit 41 to detect the occurrence of an event.

[0057] When the event detection unit 43 detects the occurrence of an event, the recording control unit 44 records image data 31 for a predetermined period before and after the occurrence of the event, including the time when the event occurred, in the storage recording medium 50. The threshold update unit 45 obtains the maximum value of the detection value of the vibration of the vehicle V for each unit section, which is a predetermined time or distance over which the vehicle V travels. It calculates the threshold to be used in the next unit section based on the maximum detection value. It updates the threshold set by the threshold setting unit 41.

[0058] As a result, for each unit section in which the vehicle V travels, the maximum detection value of the vibration of the vehicle V detected by the vibration detection unit is found, excluding detection values ​​that exceed the threshold, and the threshold to be used in the next unit section is updated based on the maximum detection value. That is, the threshold value of the vibration of the vehicle V for detecting the occurrence of an event can be set based on the vibration of the vehicle V detected in the immediately preceding unit section. The threshold value of the vibration of the vehicle V can be set by reflecting the road conditions of the immediately preceding unit section. As a result, it is possible to suppress the determination that an event has occurred when the vibration of the vehicle V exceeds the threshold due to shaking on a rough road or vibration specific to the vehicle when there is no abnormality such as a collision, and to reduce unnecessary event recording.

[0059] [Second embodiment] Next, a second embodiment of the present invention will be described. As described above, the imaging device 1 according to the first embodiment obtains the maximum positive and negative detection values ​​of the vibration of the vehicle V, excluding detection values ​​that exceed the positive or negative threshold value for each unit section while the vehicle V is traveling. Then, based on the maximum positive and negative detection values ​​of the vibration of the vehicle V obtained for each unit section, the positive and negative threshold values ​​to be used in the next unit section are calculated, and the positive and negative threshold values ​​set by the threshold setting unit 41 are updated as needed.

[0060] In contrast, the imaging device 1 according to the second embodiment acquires position information of the vehicle V, and records predetermined position information of a unit section in association with the maximum positive and negative detection values ​​of the vibration of the vehicle V obtained for each unit section. Then, when traveling through a unit section in which the vehicle V has traveled in the past and the maximum positive and negative detection values ​​of the vibration of the vehicle V were recorded, the positive and negative threshold values ​​are set based on the maximum positive and negative detection values ​​of the vibration of the vehicle V recorded in association with the predetermined position information of that unit section.

[0061] Hereinafter, a configuration example of the imaging device 1 according to the second embodiment will be described with reference to Fig. 5. As shown in Fig. 5, the second embodiment differs from the first embodiment in that the imaging device 1 further includes a GNSS receiver 60, and the CPU 40 of the imaging device 1 further includes a determination unit 46 and an information recording unit 47. Configurations that overlap with those of the first embodiment will be referred to by reference numerals and their description will be omitted. Below, the differences from the first embodiment will be mainly described.

[0062] The GNSS receiver 60 is a GPS receiver or the like, and detects the position of the vehicle on the ground by receiving radio waves from multiple artificial satellites. The GNSS receiver 60 functions as a position information acquisition unit for the vehicle V. The GNSS receiver 60 acquires the position information of the vehicle V at a frequency of, for example, 1 Hz. The GNSS receiver 60 temporarily records the detected position information of the vehicle V in the internal memory 30. Note that "GPS" is an abbreviation for "Global Positioning System." Here, the position of the vehicle V is calculated within the GNSS receiver 60, but the CPU 40 may calculate the position of the vehicle V.

[0063] The information acquisition unit 42 of the CPU 40 according to the second embodiment acquires position information of the vehicle V detected by the GNSS receiver 60. The information acquisition unit 42 acquires current position information of the vehicle V.

[0064] Further, the information acquisition unit 42 acquires predetermined position information of the unit section. For example, the information acquisition unit 42 acquires position information of the vehicle V at the start of the unit section when the vehicle V travels through the unit section as the predetermined position information of the unit section. The information recording unit 47 may acquire position information of the vehicle V at the middle of the unit section as the predetermined position information of the unit section, or may acquire position information of the vehicle V at a plurality of time points in the unit section as the predetermined position information of the unit section, such as position information of the vehicle V at the start and end of the unit section. The method of setting the predetermined position of the unit section is not particularly limited.

[0065] The information recording unit 47 records the maximum positive and negative detection values ​​of the vibration of the vehicle V obtained for each unit section by the threshold update unit 45 in association with predetermined position information of the unit section. When the determination unit 46 described later determines that the vehicle V is traveling through a unit section that it has traveled through in the past, the information recording unit 47 updates the maximum positive and negative detection values ​​of the vibration of the vehicle V and the predetermined position information of the unit section that were recorded when the vehicle V traveled through the same unit section in the past to the maximum positive and negative detection values ​​of the vibration of the vehicle V and the predetermined position information of the unit section obtained when the vehicle V traveled through the unit section this time.

[0066] The information recording unit 47 associates the maximum positive and negative detected values ​​of the vibration of the vehicle V for each unit section with predetermined position information of the unit section, and records them in a storage area different from the event storage area of ​​the recording medium 50. The information recording unit 47 may also associate the maximum positive and negative detected values ​​of the vibration of the vehicle V with predetermined position information of the unit section, and record them in the internal memory 30. Alternatively, the information recording unit 47 may also record them in a memory different from the recording medium 50 and the internal memory 30.

[0067] The determination unit 46 determines whether the vehicle V will travel through a unit section that has traveled in the past, based on the predetermined position information of the unit section recorded by the information recording unit 47 and the current position information of the vehicle V. For example, the determination unit 46 determines that the vehicle V will travel through a unit section that has traveled in the past, when the current position of the vehicle V is within a predetermined range from the predetermined position of the unit section recorded by the information recording unit 47. When a plurality of pieces of predetermined position information of the unit section are recorded, the determination unit 46 may determine that the vehicle V will travel through a unit section that has traveled in the past, when the current position of the vehicle V is between the predetermined positions of the plurality of recorded unit sections.

[0068] The threshold setting unit 41 sets initial thresholds that are set in advance as positive and negative thresholds when the vehicle V starts traveling. When the determination unit 46 determines that the vehicle V is traveling through a unit section that has been traveled in the past, the threshold setting unit 41 sets the positive and negative thresholds based on the maximum positive and negative detection values ​​of the vibration of the vehicle V recorded in association with predetermined position information of the unit section. The threshold setting unit 41 calculates the positive and negative thresholds by multiplying the maximum positive and negative detection values ​​of the vibration of the vehicle V recorded in association with predetermined position information of the unit section by a predetermined multiple. The threshold setting unit 41 sets the calculated positive and negative thresholds as the positive and negative thresholds for determining whether an event has occurred when traveling through the unit section this time.

[0069] When the judgment unit 46 determines that the vehicle V will not travel through a unit section that it has traveled in the past, and the positive and negative thresholds were updated by the threshold update unit 45 when it traveled through the immediately previous unit section, the threshold setting unit 41 sets the updated positive and negative thresholds as the positive and negative thresholds for determining whether an event has occurred, as in the first embodiment.

[0070] 6, an example of the operation of the information acquisition unit 42, the determination unit 46, the information recording unit 47, the threshold setting unit 41, and the threshold update unit 45 will be described. Note that the operation of the event detection unit 43 and the recording control unit 44 is similar to that of the first embodiment, and therefore the description thereof will be omitted.

[0071] Fig. 6 shows an image of the detection value G of the vibration of the vehicle V (hereinafter simply referred to as the detection value G) and the positive and negative threshold values ​​for each unit section D1 to D3 when the vehicle V travels for the second time along the road shown in Fig. 2 on which the vehicle V has traveled in the past. Note that the vertical axis of Fig. 6 shows the detection value, and the horizontal axis shows the distance.

[0072] The information recording unit 47 associates and records the positive and negative maximum values ​​M1a, M1b found in unit section D1 by the threshold updating unit 45 when traveling through unit sections D1 to D3 last time, and the position information of point A, which is a predetermined position in unit section D1, obtained by the information acquiring unit 42. The information recording unit 47 associates and records the positive and negative maximum values ​​M2a, M2b found in unit section D2 by the threshold updating unit 45, and the position information of point B, which is a predetermined position in unit section D2, obtained by the information acquiring unit 42. The information recording unit 47 associates and records the positive and negative maximum values ​​M3a, M3b found in unit section D3 by the threshold updating unit 45, and the position information of point C, which is a predetermined position in unit section D3, obtained by the information acquiring unit 42.

[0073] 6, vehicle V starts traveling from point A, as in the previous traveling, and travels unit section D1, which is a predetermined distance from point A to point B. After traveling unit section D1, it travels unit section D2, which is a predetermined distance from point B to point C. After traveling unit section D2, it travels unit section D3, which is a predetermined distance from point C to point D.

[0074] At point A where the vehicle V starts traveling, the threshold setting unit 41 sets preset initial thresholds THa and THb as positive and negative thresholds for detecting the occurrence of an event.

[0075] The information acquisition unit 42 acquires current position information of the vehicle V at the point A.

[0076] The judgment unit 46 judges that the vehicle V is traveling through the unit section D1 that it has previously traveled when the position of the vehicle V obtained at point A is within a specified range from the position of point A, which is a specified position of the unit section D1 recorded by the information recording unit 47 during the previous travel.

[0077] The threshold setting unit 41 calculates positive and negative thresholds TH1a', TH1b' by multiplying the positive and negative maximum values ​​M1a, M1b recorded in association with the position information of point A, which is a predetermined position in unit section D1 during the previous travel, by a predetermined multiple "3". Then, the calculated positive and negative thresholds TH1a', TH1b' are set as the positive and negative thresholds for the current unit section D1.

[0078] The threshold updating unit 45 determines that the vehicle V has traveled through the unit section D1 when the vehicle V reaches the point B, and calculates the maximum values ​​M1a', M1b' of the positive and negative detection values ​​G within the unit section D1 that has been traveled this time. The threshold updating unit 45 multiplies the calculated maximum values ​​M1a', M1b' by a predetermined multiple "3" to calculate the positive and negative threshold values ​​TH2a, TH2b to be used in the next unit section D2. Then, the positive and negative threshold values ​​TH1a', TH1b' set by the threshold setting unit 41 are updated to the calculated positive and negative threshold values ​​TH2a, TH2b.

[0079] The information acquisition unit 42 acquires the current position information of the vehicle V at the point A as the predetermined position information of the current unit section D1. The information recording unit 47 updates the position information of the positive and negative maximum values ​​M1a, M1b and the point A which is the predetermined position of the unit section D1, which were recorded when the vehicle V traveled the previous time through the unit section D1, to the currently obtained positive and negative maximum values ​​M1a', M1b' and the currently acquired position information of the point A which is the predetermined position of the unit section D1.

[0080] The vehicle V then travels through the unit section D2. At the point B, the information acquisition unit 42 acquires the current position information of the vehicle V.

[0081] The judgment unit 46 judges that the vehicle V is traveling through the unit section D2 that it has previously traveled when the current position of the vehicle V obtained at point B is within a specified range from the position of point B, which is a specified position of the unit section D2 recorded by the information recording unit 47 during the previous travel.

[0082] The threshold setting unit 41 calculates the positive and negative thresholds TH2a', TH2b' by multiplying the positive and negative maximum values ​​M2a, M2b recorded in association with the position information of point B, which is a predetermined position in the unit section D2 during the previous travel, by a predetermined multiple "3". Then, the calculated positive and negative thresholds TH2a', TH2b' are set as the positive and negative thresholds in the current unit section D2.

[0083] The threshold updating unit 45 determines that the vehicle V has traveled through the unit section D2 when the vehicle V reaches the point C, and calculates the maximum values ​​M2a', M2b' of the positive and negative detection values ​​G within the unit section D2 that has been traveled this time. The threshold updating unit 45 multiplies the calculated maximum values ​​M2a', M2b' by a predetermined multiple "3" to calculate the positive and negative threshold values ​​TH3a, TH3b to be used in the next unit section D3. Then, the positive and negative threshold values ​​TH2a', TH2b' set by the threshold setting unit 41 are updated to the calculated positive and negative threshold values ​​TH3a, TH3b.

[0084] The information acquisition unit 42 acquires the position information of the vehicle V at the point B as the predetermined position information of the current unit section D2. The information recording unit 47 updates the position information of the positive and negative maximum values ​​M2a, M2b and the point B which is the predetermined position of the unit section D2, which were recorded when the vehicle V traveled the previous unit section D2, to the currently obtained positive and negative maximum values ​​M2a', M2b' and the currently acquired position information of the point B which is the predetermined position of the unit section D2.

[0085] The vehicle V then travels through the unit section D3. At the point C, the information acquisition unit 42 acquires the current position information of the vehicle V.

[0086] The judgment unit 46 judges that the vehicle is traveling through the unit section D3 that it has previously traveled when the current position of the vehicle V obtained at point C is within a specified range from the position of point C, which is a specified position of the unit section D3 recorded by the information recording unit 47 during the previous travel.

[0087] The threshold setting unit 41 calculates the positive and negative thresholds TH3a', TH3b' by multiplying the positive and negative maximum values ​​M3a, M3b recorded in association with the position information of point C, which is a predetermined position in the unit section D3 during the previous travel, by a predetermined multiple "3". Then, the calculated positive and negative thresholds TH3a', TH3b' are set as the positive and negative thresholds in the current unit section D3.

[0088] The threshold updating unit 45 determines that the vehicle V has traveled through the unit section D3 when the vehicle V reaches the point D, and calculates the maximum values ​​M3a', M3b' of the positive and negative detection values ​​G within the unit section D3 that has been traveled this time. Thereafter, the same process is repeated to update the positive and negative thresholds for each unit section.

[0089] The information acquisition unit 42 acquires the position information of the vehicle V at the point C as the predetermined position information of the current unit section D3. The information recording unit 47 updates the position information of the positive and negative maximum values ​​M3a, M3b and the point C, which is the predetermined position of the unit section D3, recorded when the vehicle traveled the previous unit section D3, to the currently obtained positive and negative maximum values ​​M3a', M3b' and the currently acquired position information of the point C, which is the predetermined position of the unit section D3. Thereafter, the same operation is repeated to update the positive and negative maximum values ​​and the predetermined position information of the unit section for each unit section.

[0090] This makes it possible to set a threshold value for the vibration of the vehicle V to detect the occurrence of an event by referring to the maximum positive and negative vibration values ​​of the vehicle V when it traveled the same unit section in the past, thereby improving the accuracy of detecting the occurrence of an event in a certain unit section.

[0091] [Processing flow of the imaging device] Next, an example of the flow of processing executed by the CPU 40 of the imaging device 1 according to the second embodiment will be described with reference to the flowchart of Fig. 7. The CPU 40 starts the processing of Fig. 7 at the timing when the vehicle V starts to travel. Step S201 of Fig. 7 is the same processing as step S10 of Fig. 4, and steps S205 to S211 of Fig. 7 are the same processing as steps S11 to S17 of Fig. 4, so their description will be omitted.

[0092] In step S202, the information acquisition unit 42 acquires position information of the vehicle V detected by the GNSS receiver 60. The information acquisition unit 42 acquires current position information of the vehicle V.

[0093] The process proceeds to step S203, where the determination unit 46 determines whether the vehicle V will travel through a unit section that has traveled in the past, based on predetermined position information of the unit section previously recorded by the information recording unit 47 and the current position information of the vehicle V. For example, when the current position of the vehicle V is within a predetermined range from the predetermined position of the unit section previously recorded, the determination unit 46 determines that the vehicle V will travel through a unit section that has traveled in the past. If the vehicle V will travel through a unit section that has traveled in the past (YES in step S203), the process proceeds to step S204. On the other hand, if the vehicle V will not travel through a unit section that has traveled in the past (NO in step S203), the process proceeds to step S205.

[0094] In step S204, the threshold setting unit 41 sets positive and negative thresholds based on the maximum positive and negative detection values ​​previously recorded in association with predetermined position information of the unit section. The threshold setting unit 41 calculates the positive and negative thresholds by multiplying the maximum positive and negative detection values ​​previously recorded in association with predetermined position information of the unit section by a predetermined multiple. The threshold setting unit 41 sets the calculated positive and negative thresholds as the positive and negative thresholds for determining whether an event has occurred. After that, the process proceeds to step S205.

[0095] In step S212, the information acquisition unit 42 acquires predetermined position information of the unit section. For example, the information acquisition unit 42 acquires position information of the vehicle V at the start of the unit section when the vehicle V travels through the unit section as the predetermined position information of the unit section.

[0096] The process proceeds to step S213, where the information recording unit 47 records the maximum positive and negative detection values ​​obtained by the threshold updating unit 45 in step S209 and the predetermined position information of the unit section obtained by the information acquiring unit 42 in step S212 in association with each other. When the determining unit 46 determines in step S203 that the vehicle V is traveling through a unit section that it has traveled in the past, the information recording unit 47 updates the maximum positive and negative detection values ​​and the predetermined position information of the unit section recorded when the vehicle V traveled through the same unit section in the past to the maximum positive and negative detection values ​​obtained in step S209 and the predetermined position information of the unit section obtained in step S212.

[0097] After completing the process of step S213, the CPU 40 thereafter repeats the processes of steps S202 to S213 in FIG. 7 until the vehicle V stops traveling and the imaging device 1 is powered off.

[0098] [Effects of the second embodiment] As described above, the imaging device 1 according to the second embodiment further includes a position information acquisition unit (GNSS receiver) 60, an information recording unit 47, and a determination unit 46. The position information acquisition unit 60 acquires position information of the vehicle V. The information recording unit 47 records the maximum value of the detection value obtained for each unit section by the threshold update unit 45 in association with the predetermined position information of the unit section. The determination unit 46 determines whether the vehicle V will travel through a unit section that has traveled in the past, based on the current position information of the vehicle V and the predetermined position information of the unit section. When the determination unit 46 determines that the vehicle V will travel through a unit section that has traveled in the past, the threshold setting unit 41 sets positive and negative thresholds based on the maximum value of the positive and negative detection values ​​recorded in association with the predetermined position information of the unit section.

[0099] The maximum detection value of the vibration of the vehicle V obtained for each unit section is associated with and recorded as specified position information of the unit section. When it is determined that the vehicle V is traveling through a unit section that it has traveled in the past based on the current position information of the vehicle V and the specified position information of the unit section, the maximum detection value of the vibration of the vehicle V recorded in association with the position information of the vehicle V can be set as the vibration threshold of the vehicle V for detecting the occurrence of an event in the unit section. This makes it possible to set the vibration threshold of the vehicle V for detecting the occurrence of an event by referring to the maximum detection value of the vibration of the vehicle V when it traveled through the same unit section in the past. This makes it possible to improve the accuracy of detecting the occurrence of an event in a certain unit section.

[0100] In addition, when it is determined that the vehicle V is traveling through a unit section that it has traveled in the past, the maximum vibration detection value of the vehicle V and the predetermined position information of the unit section recorded when it traveled through the same unit section in the past are updated to the maximum detection value and the predetermined position information of the unit section obtained when it traveled through the unit section this time. This makes it possible to set a threshold value for detecting the occurrence of an event that always reflects the latest road conditions in the same unit section. This makes it possible to further improve the accuracy of detecting the occurrence of an event in a certain unit section.

[0101] As described above, the embodiment of the present invention has been described, but the description and drawings forming a part of this disclosure should not be understood as limiting this invention. From this disclosure, various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art. [Explanation of symbols]

[0102] 1. Imaging device 10. Imaging unit 20 Vibration detection unit (accelerometer) 30 Internal Memory 31 Image data 40 CPU 41 Threshold setting unit 42 Information Acquisition Department 43 Event detection section 44 Recording control section 45 Threshold Update Unit 46 Judgment section 47 Information Recording Section 50 Recording media 51 Image data 60 GNSS receivers V Vehicle

Claims

1. an imaging unit that captures an image of the interior or exterior of a vehicle and generates image data; A vibration detection unit that detects vibrations of the vehicle; a threshold setting unit that sets a threshold for determining whether or not an event that requires the image data to be stored has occurred based on a detection value of the vibration of the vehicle detected by the vibration detection unit; an event detection unit that detects the occurrence of the event by comparing a detection value of the vibration of the vehicle detected by the vibration detection unit with a threshold value set by the threshold setting unit; a recording control unit that, when the event detection unit detects the occurrence of the event, records the image data for a predetermined period before and after the occurrence of the event, including the time when the event occurred, in a storage medium for storage; a threshold updating unit that obtains a maximum value of a detection value of vibration of the vehicle for each unit section which is a predetermined time or a predetermined distance during which the vehicle travels, calculates a threshold to be used in the next unit section based on the maximum detection value, and updates the threshold set by the threshold setting unit; An imaging device comprising:

2. a location information acquisition unit that acquires location information of the vehicle; an information recording unit that records the maximum value of the detection value obtained for each unit section by the threshold updating unit and predetermined position information of the unit section in association with each other; a determination unit that determines whether the vehicle is traveling through a unit section that has been traveled in the past, based on current position information of the vehicle and predetermined position information of the unit section; Further equipped with When the determination unit determines that the vehicle is traveling through a unit section that has been traveled in the past, the threshold setting unit sets the threshold based on a maximum value of the detection value recorded in association with predetermined position information of the unit section. The imaging device according to claim 1 .

3. Acquire the vehicle vibration detected by the vibration detection unit; setting a threshold value for determining whether or not an event has occurred that requires image data generated by an imaging unit by imaging the interior or exterior of the vehicle to be stored, based on the detection value of the vibration of the vehicle; comparing the detected value of the vibration of the vehicle with the set threshold value to detect the occurrence of the event; When the occurrence of the event is detected, the image data for a predetermined period before and after the occurrence of the event, including the time when the event occurred, is recorded in a storage medium for storage; A maximum value of the detection value is obtained for each unit section, which is a predetermined time or a predetermined distance, during which the vehicle travels, and a threshold value to be used in the next unit section is calculated based on the maximum detection value, thereby updating the set threshold value. A method for controlling an imaging device.

4. The computer installed in the imaging device acquiring a vibration of the vehicle detected by a vibration detection unit; setting a threshold value for determining whether or not an event has occurred that requires image data generated by an imaging unit by imaging the interior or exterior of the vehicle to be stored, based on a detection value of the vibration of the vehicle; a step of detecting the occurrence of the event by comparing a detected value of the vibration of the vehicle with the set threshold value; when occurrence of the event is detected, recording the image data for a predetermined period before and after the occurrence of the event, including the time when the event occurred, in a storage medium for storage; determining a maximum value of the detection values ​​for each unit section, which is a predetermined time or distance traveled by the vehicle, calculating a threshold value to be used in the next unit section based on the maximum detection value, and updating the set threshold value; A control program for the imaging device that causes the imaging device to execute the above steps.

Images